https://gescco.com/en/Public technical records on systems, networking and reliabilityenhttps://gescco.com/en/notes/linux-first-look/https://gescco.com/en/notes/linux-first-look/Use load, CPU, memory and I/O together to distinguish compute contention from blocked work.LinuxSat, 03 Oct 2026 15:00:00 GMThttps://gescco.com/en/notes/backup-restore/https://gescco.com/en/notes/backup-restore/Use PostgreSQL logical backups to connect integrity checks, restore drills and RPO / RTO.Data & reliabilitySat, 03 Oct 2026 15:00:00 GMThttps://gescco.com/en/notes/dns-debugging/https://gescco.com/en/notes/dns-debugging/Check NS, A/AAAA, CNAME and TTL to distinguish incorrect records, cache differences and connection failures.Networking & proxiesSat, 03 Oct 2026 15:00:00 GMThttps://gescco.com/en/notes/incident-notes/https://gescco.com/en/notes/incident-notes/Organize investigation around impact, a timeline and tested hypotheses, then make improvements trackable.Data & reliabilitySat, 03 Oct 2026 15:00:00 GMThttps://gescco.com/en/notes/kubernetes-crashloop/https://gescco.com/en/notes/kubernetes-crashloop/Connect termination reasons, previous logs, events and probes before restarting hides the evidence.KubernetesSat, 03 Oct 2026 15:00:00 GMThttps://gescco.com/en/notes/nginx-upstream/https://gescco.com/en/notes/nginx-upstream/Use error logs to distinguish connection and response failures, then check upstream health, connections and timeouts.Networking & proxiesSat, 03 Oct 2026 15:00:00 GMThttps://gescco.com/en/notes/openvpn-tcp-udp/https://gescco.com/en/notes/openvpn-tcp-udp/Set up OpenVPN on Ubuntu with complete UDP and TCP server and client configurations, covering certificates, forwarding, DNS, full-tunnel egress and certificate revocation.Networking & proxiesSat, 03 Oct 2026 15:00:00 GMThttps://gescco.com/en/notes/prometheus-latency/https://gescco.com/en/notes/prometheus-latency/Calculate P95 correctly for classic histograms and investigate traffic, errors and latency together.ObservabilitySat, 03 Oct 2026 15:00:00 GMThttps://gescco.com/en/notes/safe-rollout/https://gescco.com/en/notes/safe-rollout/Prepare version history, an observation window and rollback actions for a release you can verify.KubernetesSat, 03 Oct 2026 15:00:00 GMThttps://gescco.com/en/notes/strongswan-ikev2-vpn/https://gescco.com/en/notes/strongswan-ikev2-vpn/Build a password-authenticated remote-access VPN with swanctl, covering certificates, address pools, firewall rules, split routing and DNS, with lessons from maintaining older installations.Networking & proxiesSat, 03 Oct 2026 15:00:00 GMT